The warm start option controls the linear solver that is used by the branch-and-bound solver at each node of the solution tree when a previous solution is present to use as a "warm start". The cold start option determines the solver to use when a previous solution does not exist.

There are four possible settings for REOPTB:

REOPTB

Value

 

Warm Start Solver

0

LINGO Decides – LINGO chooses the most appropriate solver.

1

Primal  – The primal solver will be used exclusively.

2

Dual – The dual solver will be used exclusively..

3

Barrier – LINGO uses the barrier method, assuming you have purchased a license for the barrier solver. Otherwise, the dual solver will be used.

In general, LINGO Decides will yield the best results. The barrier solver can’t make use of a pre-existing solution, so Barrier usually won’t give good results. In general, Dual will be faster than Primal for reoptimization in branch-and-bound.